This invention relates generally to typewriters and printers which utilize multicharacter, fully-formed print elements or which form characters by a matrix of dots, and more particularly to a printer arrangement wherein a mark is formed by causing ink to depart from a layer on a ribbon and depositing upon a receiving surface.
It is well known that business employs a variety of printers and typewriters to produce easily-readable information on paper. This information can be in the form of text, graphs, diagrams, or even pictures. In many offices, such printed output is then transported to a photocopier wherein copies are made for distribution, rather than making several copies on the printers that produced the original information sheet. It is also well known that the act of photocopying often reduces the quality of the information, when compared with the original image, so that it is important for the office operator of the typewriter or printer to produce the very best original image of the information that is possible.
Once the equipment used for printing originals has been carefully adjusted, either for thermal or impact printing action, much of the remaining quality is determined by the choices of ribbon and output paper. The ribbon is generally either a film of ink coated on a thin plastic layer, or an investment of ink dispersed in a fabric ribbon which is typically thicker than the thin plastic layer. The film ribbon can be used with either thermal or impact printing system, by appropriate selection of the plastic film and the ink formulation. The fabric ribbon, however, is used only with impact printing systems of the type using either fully-formed characters or a dot matrix character-forming process. The ink color can be black, as by admixture of carbon particles, or any of several other colors produced by dyestuff mixture.
While the majority of applications require black or colored ink for producing originals which have their utility in providing readable information, some office or business printers produce special printed materials that will be scanned for information by machines. For example, when negotiable instruments such as checks are to be read by high speed sorting equipment, they are generally imprinted using a dark ink with special magnetic properties. The characters used can be read by humans and machines to yield information relating usually to numeric values of the transaction, account numbers, issuing bank number, and other internal transfer information. These check imprint characters are, in the United States, approved by the American Banking Association and called Magnetic Ink Character Recognition or MICR. While it is most common for a bulk printing operation to encode checks with the basic MICR information, it is not uncommon to provide manually-operated printers and typewriters to make up special checks, or to provide bank customers with temporary supplies of MICR-encoded documents until the printer can supply a larger quantity.
Colored inks have been used for highlighting the darker text characters, with red being the most commonly used highlighting color. Some printing equipment may use two separate ribbons, one of a dark color, such as black, and the other red. Other equipment may use either two separate ribbons, or an easily replaceable cartridge with such cartridges supplied with ribbon in any of several colors, including black. Some known ribbons for typewriters or adding machine are made of fabric with a top band of black ink and a lower band of red ink; the desired ink color being selected by vertical positioning of the ribbon at the printing zone of the printer or typewriter. A few printers use sections of ribbons which bear different color inks, for example, the largest center section having black ink, add end sections having red, yellow, blue, and green inks available. These multisection ribbons use longitudinal positioning to select either basic text color or a highlighting color, as desired, with incremental stepping to position an unused portion of ribbon for character formation within the desired color section.
It is also well known that ribbons may be produced which can have either single or multiple use characteristics. Film ribbons can be produced which release all of their ink layer upon one impact, called "full-release ribbons." This type of film ribbon is preferred when the maximum quality imprint is required. Other film ribbons have, in effect, a multilayer characteristic, in which several impacts in substantially the same area can each yield a good quality image This multilayer effect allows the ribbon to provide more output images per unit area, but the print quality is not quite as dark and crisp as that of the single layer, full-release film ribbon. Most thermal transfer printers cause deposition of the entire layer of ink from the ribbon when heat is applied, so that these printers employ single use ribbons. Fabric ribbons are considered to be multistrike ribbons, since the ink can migrate from an unused portion of the ribbon to replenish the ink in a region in which character-forming impact has removed some portion of the ink deposited therein during manufacturing. While fabric ribbons can generally deliver more impact images per unit area than can fabric ribbons, the thickness of the fabric layer is several times that of the film layer. Accordingly, the character thus formed will not have as distinct a quality, and often the ink will not be quite as dark as would result by using a high carbon content film ribbon.
There is a demand for a more accurately controlled ribbon transport system as the need for a larger variety of printing tasks to be performed by a single office machine increases. Such a need is intensified as printing equipment speed increases so as to provide more information output from a single machine. The need for better ribbon control is evident at least from the fact that it is now very common to construct a complete document, perhaps only viewing it on an informational display, such as a cathode-ray tube, thus providing review for correction and layout formatting. Once the document is deemed satisfactory, the corrected information is then passed to a printer, with the hope that the printer will perform the indicated task. If the output pages are to have a special quality, such as the very best image darkness and edge sharpness that the particular printer can produce, a single release film ribbon is generally selected.
Inasmuch as ribbons for many printers, are provided in cartridges, and the cartridges for the various printers oftentimes look very much alike, it is important that the correct type of cartridge be installed on the printer. Often, it is left to the operator to be very careful to select the proper ribbon, and it is a problem that there is not in widespread commercial use a machine-readable system for indicating that a mistake in ribbon cartridge selection has occurred. These mistakes in cartridge selection are quite common since a single release ribbon and a multistrike ribbon look entirely similar, and generally only upon reading the model number or looking on either the outer wrapper or the packaging box will the type of ribbon contained therein be indicated. Moreover, when ribbons are used that have several color sections, if the dark portion is in place, it is easy to mistake a colored section ribbon for an all-black ribbon The price of these ribbon mis-selections is at least the time and cost of producing an unusable document, the time lost in replacing the ribbon, and the waste of the used ribbon itself.
In currently available printer systems, when a multicolor ribbon using the longitudinal section color system is used, the present practice is to use a shaft encoder to monitor ribbon positioning. As printer equipment is required to achieve faster printout speeds, it is a further problem that the demands for ribbon positioning at high speeds results in mispositioning caused by slippage between the shaft encoders which intermittently jam when waste particles of ink left over from the impact printing gather in a gear or in a bearing so as to increase drive friction.
There is a developing need in the printer art for printing equipment which is utilized in a remote manner, by the transmission of print commands from an operator's terminal which may be several feet, or very distant, from the printing equipment. It is a problem that a signal is not provided to such a remote operator indicating the ribbon type installed on the printer, or the quantity remaining. Generally, no signal is produced until the end of the ribbon or a required color section has been reached. The present state of the art does, however, provide a remote signalling arrangement which operates to inhibit further printing. Since printer stoppage usually occurs without a warning, the operator may request a printout of a several page document and have no warning of insufficient ribbon to complete a job until a signal such as "ribbon out" is received. This will usually not cause any physical damage, but it will usually spoil the partially-printed page and thereafter a new ribbon must be inserted when someone notices the signal and restarts that page.
Since remote operation is increasingly desired, thereby permitting several operators to create text and documents at their respective work stations and share a relatively expensive printer, it is a problem that no one operator can have knowledge at the work station of the amount of ribbon available for printing. Even if one wished to go to the printer and look, the ascertainment of the remaining amount of ribbon in a printer is a frustrating experience. First, the ribbon box is usually located under a cover, and if the printer is in use by another, the raising the cover will usually stop or spoil the printing of a job in progress. Second, once in view, there may be no opening in the cartridge through which the ribbon reels can be seen. Third, if an opening in the ribbon cartridge has been provided, it is difficult to estimate just how much ribbon remains, and how many documents might be produced, even if only one operator were to demand output documents, rather than have the usual intermix of job orders.
In modern offices, one of the major justifications for computer-based equipment, such as word processing stations, perhaps with remote printers, is both, to facilitate the normal flow of work, and especially to facilitate handling of sudden emergency needs. These emergency jobs are the most critical from a time pressure standpoint, and the unplanned interruption of a "ribbon-out" signal or a document produced in a mixture of colors by mistakenly placing a longitudinal color mix ribbon instead of the desired all-black ribbon, thus producing a completely unusable document, is certain to cause much frustration. It therefore would be preferable from the standpoint of increasing job efficiency if the control terminal were to be provided with information that would indicate if: (1) the correct ribbon was in place, and (2) how much ribbon remains. It is particularly essential to know whether the amount of remaining ribbon is sufficient to complete the intended job. If not, the ribbon could be replaced before the job starts, or a smaller job could be selected out of sequence to use up the last remaining portion of ribbon in the cartridge or spool.
There is also a need for improved manufacturing control while producing ribbons, particularly when the ribbon may have several colors or types of ink emplaced on the one base stock. If the longitudinal section method of color or special ribbon type is to be used, it is very important that the manufacturer be able to communicate to the user which capabilities were emplaced and in which locations. It is a problem that no such machine readable encodement is provided in the art, and thus the desired communication does not occur. Manufacturers may decide to change ribbon length and customers may not notice the change until after a spoiled printout has occurred.
It is, therefore, an object of this invention to provide an indicia marking that will allow machine sensing of ribbon type during the complete use period of that ribbon.
It is a further object of this invention to provide an indicia marking that will allow machine sensing of the amount of ribbon of a particular type that has been used.
It is another object of this invention to produce an indicia marking on the ribbon that will instruct the printer as to the capabilities of the ribbon in the cartridge or spool emplaced therein.
It is also a further object of this invention to provide indicia that will aid manufacturing control of ribbon to ensure that proper ribbon type admixture and intended length occur.
It is a still further object of this invention to provide machine-readable indicia such that remote operators of printers can transmit information about ribbon type and quantity so as to be able to plan job flow without interruption or printing errors.